Fastening structure for securing stator of motor

ABSTRACT

A fastening structure for securing a stator of a motor includes a sleeve with a cut portion formed thereon and a fastener. The fastener is composed of a position section and an engaging section, wherein the engaging section engages with the cut portion and the position section presses on the top surfaces of the coil bobbin of the stator.

BACKGROUND OF THE INVENTION

[0001] This application is a continuation-in-part application of U.S.patent application Ser. No. 10/437,145, filed on May 12, 2003. Theentire contents of the related application are incorporated herein byreference.

[0002] 1. Field of the Invention

[0003] The invention relates to a fastening structure for the stator ofa motor and, in particular, to a fastening structure for the stator of amotor, which can prevent the stator from falling off by means of afastener

[0004] 2. Description of the Related Art

[0005] The stator of a motor is liable to fall off if the assemblystrength of the motor is not high enough to withstand the continuousvibration during a long period of operation. In view of this, if one canprovide a fastening structure compatible with conventional parts of amotor, the assembly strength of the motor can be enhanced significantlyat low cost.

BRIEF SUMMARY OF THE INVENTION

[0006] In view of the above, an objective of the invention is to providea fastening structure for securing the stator of a motor, which enhancesthe assembly strength of a motor by a fastener engaging with a sleeveand thus the stator can be tightly secured to the motor duringoperation.

[0007] Another objective of the invention is to provide a fasteningstructure for securing the stator of a motor, which can protect the coilby a special design of a fastener.

[0008] According to an embodiment of the invention, a fastener includesa position section and an engaging section. The two sides of theposition section of the fastener are designed to respectively touch thesleeve and the top surface of the coil bobbin. The sleeve is machined onits side surface to form a cut portion at a specific distance from thetop surface of the sleeve, which is designed to be substantially thesame as the distance from the position section to the end surface of theengaging section. Therefore, when the engaging section is inserted intothe cut portion, the two sides of the position section tightly pressagainst the sleeve and the top surface of the coil bobbin so as toenhance the assembly strength and establish a firm connection.

[0009] According to another embodiment of the invention, one side of theposition section adjacent to the coil bobbin is extended to the extentthat it can cover the whole coil of the stator, which prevents thefriction between the coil and the rotor so as to protect the coil.

[0010] According to still another embodiment of the invention, a firstcut portion is formed on the sleeve, and a second cut portion is formedinwardly at the bottom of the first cut portion. The first cut portionand second cut portion together form an L-shaped cut portion toaccommodate the engaging section of the fastener. When the engagingsection is inserted into the L-shaped cut portion of the sleeve, the twosides of the position section press tightly against the sleeve and a topsurface of the silicon steel sheet covering the coil to secure thestator of the motor.

[0011] Furthermore, the fastener may be of a circular structure, an arcstructure or a combination of a plurality of arc structures having thesame center and radius.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 is a perspective cross sectional view showing a fastener ofthe fastening structure according to an embodiment of the invention.

[0013]FIG. 2 is a sectional view showing the connection of the fastenerand components of a motor according to an embodiment of the invention.

[0014]FIG. 3 is an enlarged cross-section of the fastener shown in FIG.2, which illustrates more clearly the design of the fastening structureaccording to the embodiment of the invention.

[0015]FIG. 4 is a sectional view showing the connection of the fastenerand the components of the motor according to another embodiment of theinvention.

[0016]FIG. 5 is an enlarged cross-section of the fastener shown in FIG.4.

[0017]FIG. 6 is a sectional view showing another motor, with thearrangement of components different from that of the motor,incorporating the fastener structure of the invention.

[0018]FIG. 7 is an enlarged cross-section of the fastener shown in FIG.6.

[0019]FIG. 8 is a perspective cross sectional view showing a fasteneraccording to still another embodiment of the invention.

[0020]FIG. 9 is a perspective view showing another modification of thefastener structure according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0021] The fastening structure for securing the stator of a motoraccording to an embodiment of the invention will be describedhereinbelow with reference to the accompanying drawings, wherein thesame reference numbers refer to the same components.

[0022]FIG. 1 is a perspective cross sectional view showing a fastener 10of the fastening structure according to an embodiment of the invention.As shown in FIG. 1, the fastener 10 with a circular shape is composed ofa position section 10A and an engaging section such as a hook section10B, and both sections may be integrally formed by molding. Each of thetwo sides of the position section 10A has a particular thickness thatdepends on which component of the motor is to be assembled with. Thehook section 10B has an end surface P, and the distance h from theposition section 10A to the end surface P of the hook section 10B is asindicated in FIG. 1.

[0023]FIG. 2 is a sectional view showing the connection of the fastener10 and components of a motor 1 according to an embodiment of theinvention. FIG. 3 is an enlarged cross-section M of the fastener 10shown in FIG. 2, which illustrates more clearly the design of thefastening structure according to the embodiment of the invention.

[0024] As shown in FIG. 2, the stator 16 of the motor 1 includes a coilbobbin 14 and a coil 18. In this embodiment, the two sides of thefastener 10 connect a sleeve in the motor 1, such as a copper sleeve 12,and the coil bobbin 14 of the stator 16, respectively. Morespecifically, the two sides of the position section 10A of the fastener10 are designed to respectively touch the copper sleeve 12 and the topsurface of the coil bobbin 14 as shown in FIG. 3. The copper sleeve 12is machined on its side surface to form a cut portion such as a notch12A at a distance t from its top surface, the distance t is designed tobe substantially the same as the distance h from the position section10A to the end surface P. Therefore, when the hook section 10B isinserted into the notch 12A, the two sides of the position section 10Atightly press against the copper sleeve 12 and the top surface of thecoil bobbin 14 so as to establish a firm connection.

[0025] The vibration during the operation of the motor may cause thestator 16 to fall off due to an upward force acting thereon. Therefore,the fastening structure of this embodiment can solve the problem in themost effective way. By inserting the end surface P of the hook portion10B into the notch 12B, the resulting force with which the positionsection 10A presses against the coil bobbin 14 counteracts the upwardforce that acts on the stator 16 at point Q during vibration. Therefore,the assembly strength can be enhanced significantly, and the stator 16can thus be tightly secured to the motor.

[0026]FIG. 4 is a sectional view showing the connection of the fastener20 and the components of the motor 1 according to another embodiment ofthe invention. FIG. 5 is an enlarged cross-section N of the fastener 20shown in FIG. 4.

[0027] In this embodiment, the side of the position section 20A adjacentto the coil bobbin 14 is extended to the extent that it can cover thewhole coil 18 of the stator 16, which prevents the friction between thecoil 18 and the rotor 22 so as to protect the coil 18.

[0028]FIG. 6 is a sectional view showing another motor 2, with thearrangement of components different from that of the motor 1,incorporating the fastener structure of the invention. FIG. 7 is anenlarged cross-section O of the fastener 30 shown in FIG. 6. As shown inFIG. 6, the motor 2 includes a sleeve such as a copper sleeve 32 and asilicon steel sheet 34 for securing a coil 36, with the copper sleeve 32touching the silicon steel sheet 34. As shown in FIG. 7, the coppersleeve 32 of this embodiment is formed with a first cut portion having awidth t1 and a height h, and then inwardly forms with a second cutportion with a depth t2 at the bottom of the first cut portion. Thefirst cut portion and second cut portion together form an L-shaped cutportion on the side surface of the copper sleeve 32 to accommodate thehook section 30B of the fastener 30. When the hook section 30B isinserted into the L-shaped notch, the two sides of the position section30A respectively press against the copper sleeve 32 and the top surfaceof the silicon steel sheet 34 so as to secure the stator of the motor 2.

[0029] In view of the above, the invention can be implemented in variouskinds of motors each having different arrangement of components simplyby changing the type of the cut portion formed on the sleeve andmodifying the shape of the fastener. Although the motor 1 and the motor2 are both outer-rotor motors, one having ordinary skill in the artshould understand that the invention can be also implemented in aninner-rotor motor.

[0030]FIG. 8 is a perspective cross sectional view showing a fastener ofthe fastening structure according to still another embodiment of theinvention. The shape of the fastener according to the invention includesbut is not limited to a circular shape. For example, as shown in FIG. 8,a pair of arc structures 42 and 44 having the same center and radius canbe provided between the sleeve and the stator to achieve the objectiveof securing the stator and protecting the coil. Of course, one can onlyprovide a single arc structure between the sleeve and the stator.

[0031] Moreover, FIG. 9 shows another modification of the fastenerstructure, where the position section 50A of the fastener 50 has acircular shape while the hook section 50B thereof is composed of aplurality of arc structures having the same center and radius. It isunderstood that the number of the arc structures shown in FIG. 8 andFIG. 9 is not limited, but to satisfy the demand for a firm connection.

[0032] While the invention has been described by way of example and interms of the preferred embodiment, it should be understood that theinvention is not limited to the disclosed embodiments. To the contrary,it is intended to cover various modifications and similar arrangementsas would be apparent to those skilled in the art. Therefore, the scopeof the appended claims should be accorded the broadest interpretation soas to encompass all such modifications and similar arrangements.

What is claimed is:
 1. A fastening structure for securing a stator of amotor, comprising: a sleeve having a cut portion; and a fastener havinga position section and an engaging section, the engaging section beinginserted into the cut portion, and the position section pressing againstthe top surface of the stator and the sleeve.
 2. The fastening structureaccording to claim 1, wherein the side of the position section pressingagainst the stator extends to cover the coil of the stator.
 3. Thefastening structure according to claim 1, wherein the fastener has acircular shape.
 4. The fastening structure according to claim 1, whereinthe fastener is in the shape of an arc.
 5. The fastening structureaccording to claim 1, wherein the fastener is a combination of aplurality of arc structures having the same center and radius.
 6. Thefastening structure according to claim 1, wherein the position sectionof the fastener has a circular shape and the engaging section thereof iscomposed of a plurality of arc structures having the same center andradius.
 7. The fastening structure according to claim 1, wherein thefastener is integrally formed by molding.
 8. The fastening structureaccording to claim 1, wherein the sleeve is a copper sleeve.
 9. Thefastening structure according to claim 1, wherein the engaging sectionis a hook section.
 10. The fastening structure according to claim 1,wherein the cut portion is formed as a notch.
 11. A fastening structurefor securing a stator of a motor, the stator having a coil bobbin, thefastening structure comprising: a sleeve having a cut portion formedlaterally and inwardly on the side surface of the sleeve, the cutportion keeping a specific distance from the top surface of the sleeve;and a fastener having a position section and an engaging section, theengaging section being inserted into the cut portion, and the positionsection pressing against the top surface of the stator and the sleeve.12. The fastening structure according to claim 11, wherein the fastenerhas a circular shape.
 13. The fastening structure according to claim 11,wherein the fastener is in the shape of an arc.
 14. The fasteningstructure according to claim 11, wherein the fastener is a combinationof a plurality of arc structures having the same center and radius. 15.The fastening structure according to claim 11, wherein the fastener isintegrally formed by molding.
 16. The fastening structure according toclaim 11, wherein the sleeve is a copper sleeve.
 17. The fasteningstructure according to claim 11, wherein the engaging section is a hooksection.
 18. The fastening structure according to claim 11, wherein thecut portion is formed as a notch.
 19. A fastening structure for securinga stator of a motor, the stator having a silicon steel sheet to secure acoil of the motor, the fastening structure comprising: a sleeve having afirst cut portion and a second cut portion formed inwardly at the bottomof the first cut portion, the first cut portion and the second cutportion together forming an L-shaped cut portion; and a fastener havinga position section and an engaging section, the engaging section beinginserted into the L-shaped cut portion, and the position sectionpressing against the top surface of the silicon steel sheet and thesleeve.
 20. The fastening structure according to claim 19, wherein thefastener has a circular shape.